how to check key and value exists in map c++ code example

Example 1: c++ map key exists

if ( !(myMap.find("key") == myMap.end()) ) {	// "key" exists	
  
} else {	// not found	
  
}

Example 2: check if an element exists in a map c++

#include <iostream>
#include <unordered_map>
#include <algorithm>
 
int main()
{
    std::unordered_map<char,int> m;
 
    std::string s("abcba");
    std::for_each(s.begin(), s.end(), [&m](char &c) { m[c]++; });
 
    char ch = 's';
 
    if (m.find(ch) != m.end()) {
        std::cout << "Key found";
    } else {
        std::cout << "Key not found";
    }
 
    return 0;
}